CONFAST 1/4" x 4" Pre-Expanded Mushroom Head Tamper-Proof Masonry and Concrete Anchors, Carbon Steel Zinc Plated (Box of 100) : Amazon.ca: Tools & Home Improvement
Powers Fasteners 3272, 1/4 X 2 Inch Split Drive Tamper-Proof Pin Anchor Flat Head for Concrete
2 1/2 in x 3/16 in DeWALT Spike Mushroom Head Tamperproof Pin Anchor
Tanner - Spike Anchors are one-piece, vibration-resistant pin anchors for use in concrete, block, or stone. Available in several head styles, including tamperproof versions and anchor materials. Spike anchors are pre-formed, no